I have a KC-110 as a battery amp. Never thought that I could run the BK-9 off of a battery.

I'm surprised you wouldn't endorse the EK-50, the EW-410 I can understand. I'm wondering if I could run my old Roland E-68 off of batteries? I would rather take that on a camping trip than the BK-9.

I was eyeballing the Yamaha PSR-SX600, that seems to be a nice board, around $1000.

Casio CT-X3000 and CT-S400? are they built with quality?

What is your opinion about the Casio WK-7600? do you know anything about that? They put a lot features into it, including a 17 track sequencer, but I'm not sure about the quality of the keys and the overall craftsmanship, and most importantly, is it going to be user friendly?